I also noticed this with my HTTP-Check script (checks an URL and tells me the title, or whether it redirects to a potentially dangerous site).

6.35 was pretty quick, 7.1 takes considerably longer. I also noticed this with /dns queries, so I think it might be related to that (remember that IPv6 is now available from within mIRC).

UPnP is disabled, all ports in the configuration are unchecked, and I don't have a firewall that could affect this.